[Autofill Assistant] Fix variable name for jumbo build.

Collides with
components/autofill_assistant/browser/batch_element_checker.cc.

Broken in https://chromium-review.googlesource.com/c/1323489.

Bug: 903940
Change-Id: I8f5efa61ebc3e4ec44f9206ceff863f7082c36ba
Reviewed-on: https://chromium-review.googlesource.com/c/1330293Reviewed-by: Ganggui Tang <gogerald@chromium.org>
Commit-Queue: Eric Stevenson <estevenson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607016}

components/autofill_assistant/browser/element_area.cc

@@ -15,7 +15,7 @@ namespace autofill_assistant {
 
 namespace {
 // Waiting period between two checks.
-static constexpr base::TimeDelta kCheckPeriod =
+static constexpr base::TimeDelta kCheckDelay =
     base::TimeDelta::FromMilliseconds(100);
 }  // namespace
 
@@ -89,7 +89,7 @@ void ElementArea::KeepUpdatingPositions() {
       FROM_HERE,
       base::BindOnce(&ElementArea::KeepUpdatingPositions,
                      weak_ptr_factory_.GetWeakPtr()),
-      kCheckPeriod);
+      kCheckDelay);
 }
 
 void ElementArea::OnGetElementPosition(const std::vector<std::string>& selector,